package com.ls.nio;

import com.sun.nio.sctp.PeerAddressChangeNotification;

import org.junit.Test;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.nio.file.Paths;
import java.nio.file.StandardOpenOption;

/**
 * 一、使用 NIO 完成网络通信的三个核心：
 *
 * 1. 通道（Channel）：负责连接
 *
 * 	   java.nio.channels.Channel 接口：
 * 			|--SelectableChannel
 * 				|--SocketChannel
 * 				|--ServerSocketChannel
 * 				|--DatagramChannel
 *
 * 				|--Pipe.SinkChannel
 * 				|--Pipe.SourceChannel
 *
 * 2. 缓冲区（Buffer）：负责数据的存取
 *
 * 3. 选择器（Selector）：是 SelectableChannel 的多路复用器。用于监控 SelectableChannel 的 IO 状况
 */
public class BlockingNio {
    @Test
    public void client() throws IOException{
        //1. 获取通道
        SocketChannel sChannel = SocketChannel.open(new InetSocketAddress("127.0.0.1", 8080));

        FileChannel inChannel = FileChannel.open(Paths.get("/Users/liushuai/Desktop/1.jpg"), StandardOpenOption.READ);

        //2. 分配指定大小的缓冲区
        ByteBuffer buf = ByteBuffer.allocate(1024);

        //3. 读取本地文件，并发送到服务端
        while(inChannel.read(buf) != -1){
            buf.flip();
            sChannel.write(buf);
            buf.clear();
        }

        //4. 关闭通道
        inChannel.close();
        sChannel.close();

    }

    @Test
    public void serverSocket() throws IOException {
        //1、获取通道
        ServerSocketChannel ssChannel = ServerSocketChannel.open();
        FileChannel outChannel = FileChannel.open(Paths.get("/Users/liushuai/Desktop/2.jpg"), StandardOpenOption.WRITE, StandardOpenOption.CREATE);
        //2、绑定
        ssChannel.bind(new InetSocketAddress(8080));
        //3、获取客户端连接通道
        SocketChannel socketChannel = ssChannel.accept();
        //4、分配缓冲区
        ByteBuffer buf = ByteBuffer.allocate(1024);
        //5、接收数据
        while (socketChannel.read(buf) != -1) {
            buf.flip();
            outChannel.write(buf);
            buf.clear();
        }
        //6. 关闭通道
        socketChannel.close();
        outChannel.close();
        ssChannel.close();
    }
}

